!4 PIONEERS OF SCIENCE IN AMERICA. 



southwest, the course of the storm is from southwest to north- 

 east " that is, the air is in violent motion in Virginia before 

 it moves in Connecticut, and in Connecticut before it moves at 

 Cape Sable." In 1760 he wrote:* " Our northeast storms be- 

 gin in point of time in the southwest parts that is to say, the 

 air in Georgia, the furthest of our colonies to the southwest, 

 begins to move southwesterly before the air of Carolina, which 

 is the next colony northeastward ; the air of Carolina has the 

 same motion before the air of Virginia, which lies still more 

 northeastward ; and so on, northeasterly through Pennsyl- 

 vania, New York, New England, etc." 



Concerning the origin of springs Franklin wrote to Jared 

 Eliot, in 1747, agreeing in his view "that most springs arise 

 from rains, dews, or ponds on higher grounds; yet possibly 

 some, that break out near the tops of high, hollow mountains, may 

 proceed from the abyss, or from water in the caverns of the 

 earth, rarefied by its internal heat, and raised in vapour, till the 

 cold region near the tops of such mountains condenses the 

 vapour into water again, which comes forth as springs, and 

 rides down on the outside of the mountains as it ascended on 

 the inside." 



The mention of mountains suggested an observation that 

 the great Appalachian Mountains "show in many places, even 

 the highest parts of them, strata of seashells ; in some places 

 the marks of them are in the solid rocks. It is certainly the 

 wreck of the world we live in ! I have specimens of these sea- 

 shell rocks, broken off near the tops of the mountains, brought 

 and deposited in our library as curiosities. If you have not 

 seen the like, I will send you a piece." An observation is men- 

 tioned of " the bluff side or end of a mountain which appeared 

 striped from top to bottom," divided by Nature, as Mr. Walker 

 had told him, into pillars, of which he would be glad to have a 

 partial account from his correspondent. It was somewhere 

 near New Haven. 



The calming effect of oil on waves attracted his attention. 

 Describing some of his experiments to Dr. Brownrigg, he wrote 

 that one circumstance in them struck him with particular sur- 

 prise. This was " the sudden, wide, and forcible spreading of a 

 drop of oil on the face of the water, which I do not know that 



* In a letter to Alexander Small. 



